Objective: Determine the impact of testing for high prevalence, low penetrance gene variants associated with colorectal cancer (polymorphisms, haplotypes) on a person's quality of life (QOL), health habits, and cancer screening intentions. Methods: First-degree relatives of colorectal cancer patients and a matched group of persons without a family history of colorectal cancer from the Colorectal Cancer Familial Registry—a population-based registry in Washington State—were invited in 2006-7 to participate in a web-based survey of testing for gene variants associated with colorectal cancer risk. Participants were asked how such tests might influence their QOL, health habits, and intent to obtain colorectal cancer screening. Results: A total of 310 relatives and 170 persons without a family colorectal cancer history completed the questionnaire. For the positive genetic test scenario, 69% of respondents stated they would be “somewhat worried”; 18% said they would be “very worried.” QOL measured by the standard gamble for the carrier state was modestly lower than current health; the difference was significant only for relatives (no relatives with colorectal cancer 0.89 vs. 0.88, p=0.11; relatives with colorectal cancer 0.90 vs. 0.88, p=0.02). The difference in QOL was not significant after adjustment for sociodemographic and health factors. In the positive gene test scenario, 30% of respondents stated they would change their diet substantially, 25% would increase exercise, and 43% would start colorectal cancer screening. Relatives of colorectal cancer patients did not differ significantly from those without a family history in their reported intent to change these behaviors. Conclusion: Testing for high prevalence gene variants associated with colorectal cancer risk may increase cancer worry while only modestly influencing overall QOL. Testing could improve cancer preventive health habits and colorectal cancer screening adherence. The findings suggest that testing might reduce colorectal cancer incidence, particularly among those at higher risk for colorectal cancer.